Tuesday, August 02, 2005

Debate, evidence, consequences

The State of Nature, an exchange between Carl Pope and Bjørn Lomborg in the July issue of Foreign Policy, may be quite a useful exercise - not least because it helps keep the debate squarely in the political sphere, where it belongs.

In my view, Carl Pope has the stronger arguments, although there are some simplifications that could be abused if taken out of context (for example, "China today is experiencing riots because of its poor environmental stewardship").

One of Lomborg's seemingly stonger cards looks like the Copenhagen Consensus project whose global priority list ranks preventing HIV/Aids, ending agricultural subsidies and fighting malnutrition and malaria far above responses to climate change in terms of "where we can do the most good per dollar".

Lomborg must be aware of criticisms of the Consensus (the Copenhagen Con, I once called it), including those reported in The Economist, which championed it:

"...some members of the Consensus are dissenting. Thomas Schelling of the University of Maryland, who voted on the final choices, thinks that presenting climate change at the bottom of the list as 'bad' is misleading. He says he and the other gurus did not like Kyoto or the aggressive proposals made by Dr [William] Cline [of the Centre for Global Development], whom he sees as the 'most alarmist of the serious climate policy experts', but Dr Schelling says he would have ranked modest climate proposals higher on the list, because he sees climate as a real problem. Robert Mendelsohn, a conservative Yale economist who was an official 'critic' of the climate paper in this process, goes further: because Dr Cline’s positions are 'well out of the mainstream', he had no choice but to reject them. He worries that 'climate change was set up to fail'." (The Economist, 4 February 2005).

At least as importantly, the either/or assumptions that Lomborg makes (for example, "If investing in cookers is more cost effective than windmills, we should do the cookers first") need to be tested against specifics, and the fact that we are looking at interlocking systems where benefits and disbenefits may feedback.

Further, Lomborg states that "Most analyses show that the carbon damage cost is less than $10 per ton".

The UK Government estimated the marginal damage cost to be £70 (approx $126) in 2000 prices, within a range of £35 to £140/tC, increasing by £1/tC per year in real terms (this equates to £20.44 per tone of CO2-e (Government Economic Service Working Paper 140).

According to the Carbon 100 report from Henderson Global Investors (no relation!) , "this suggests that as much as 12% of the FTSE 100 EBITDA could be at risk, with 26 companies having a carbon exposure greater than 10% of EBITDA".